Nonenzymatic stopped-flow fluorimetric method for direct determination of uric acid in serum and urine

A simple, direct, sensitive, and selective stopped-flow method for the fluorimetric determination of uric acid in serum and urine samples is described. The variation of fluorescence intensity during the reaction between uric acid and 1,1,3-tricyano-2-amino-1-propene (triap) in the presence of hydrogen peroxide is monitored. For these kinetic measurements peroxide is monitored. For these kinetic measurements we used a versatile stopped-flow module that can be fitted to any fluorimeter. The linear range of the proposed method is 0.08-3.00 mg of uric acid per liter, and the detection limit is 0.03 mg/L. Within- and between-assay CVs and selectivity data are reported. Results for serum and urine samples correlated well with those obtained by the uricase method The proposed method is inexpensive and requires no sophisticated detection equipment.